FEMA flood zones — AE vs. X vs. VE in plain English

What NFHL is

The National Flood Hazard Layer is FEMA's authoritative geospatial database of US flood-risk zones, updated quarterly as FIRM panels are revised.

It defines Special Flood Hazard Areas (SFHAs) — places with ≥1% annual flood probability, where federally-backed mortgages require flood insurance.

Zone codes

Zone X (no shading): outside the 100-year and 500-year floodplains. Lowest premiums; flood insurance optional.

Zone X (shaded): in the 500-year (0.2% annual) floodplain. Insurance optional but recommended; some lenders ask anyway.

Zone AE: in the 100-year floodplain with established Base Flood Elevation. Mandatory insurance; pricing depends on elevation relative to BFE.

Zone A: 100-year floodplain, no BFE established. Insurance mandatory; pricing higher because elevation uncertainty.

Zone AO: shallow flooding (1-3 ft sheet flow), typically in alluvial fans + stream-adjacent flats.

Zone VE: coastal high-velocity wave zone. Highest premiums; building codes far stricter.

Zone D: undetermined. Treated like A by lenders.

Risk Rating 2.0

Since October 2021, FEMA prices flood insurance via Risk Rating 2.0 — granular, property-specific rather than zone-flat.

Two homes in the same AE zone can pay very different premiums based on distance to water, elevation, replacement cost, and flood-prevention features (e.g., proper venting in crawl spaces).

Don't assume zone = price. Get a quote.

What zipradar shows

Predominant flood zone for the ZIP centroid + sample points around it. We link to FEMA Map Service Center for any property-specific lookup.

Letter of Map Amendment (LOMA) status when public — these are the appeals where homeowners successfully argued out of an SFHA designation.